This invention relates to a camera provided with a magnetic recording device for recording specified data in a magnetic recording portion formed on a photographic film.
Generally, in such cameras, data concerning photographing information, etc. is recorded in a recording position determined for each frame. The recorded data is read during the printing operation at a photolaboratory. The read data is used as reference data in making prints or is printed on the front or rear surface of a printed sheet.
A plurality of kinds of data can be thought as those to be recorded. However, because of a limited storage capacity of the magnetic recording portion of the film, the amount of data to be recorded for each frame is also limited. Accordingly, it is difficult to record all kinds of data in the recording portion. On the other hand, the kinds of data a user desires to record differs largely depending upon the user. Accordingly, if only specified kinds of data can always be recorded, the camera cannot sufficiently respond to the user's desire. In order to solve this problem, the camera may be provided with an external designator with which the user can designate his desired kinds of data, and only the kinds of data designated by the user by means of this designator may be magnetically recorded.
With such a camera, if the user takes no trouble to designate the data, no data is recorded on the film, with the result that the data recording function cannot be fully utilized. In this case, also, if the partially exposed film is reused after being rewound, the already exposed frames may be erroneously detected to be unexposed frames because no data are written for these frames, and double exposure will occur from the first one of the erroneously detected frames.